Antarctica Ice Sheet gains mass, lowering sea level by .23mm per year.

[PC2]

A recent NASA study "challenges the conclusions of other studies, including the Intergovernmental Panel on Climate Change's (IPCC) 2013 report, which says that Antarctica is overall losing land ice."

http://phys.org/news/2015-10-mass-ga...ice-sheet.html
Full Quote:

A new NASA study says that an increase in Antarctic snow accumulation that began 10,000 years ago is currently adding enough ice to the continent to outweigh the increased losses from its thinning glaciers.

The research challenges the conclusions of other studies, including the Intergovernmental Panel on Climate Change's (IPCC) 2013 report, which says that Antarctica is overall losing land ice.

According to the new analysis of satellite data, the Antarctic ice sheet showed a net gain of 112 billion tons of ice a year from 1992 to 2001. That net gain slowed to 82 billion tons of ice per year between 2003 and 2008.

"We're essentially in agreement with other studies that show an increase in ice discharge in the Antarctic Peninsula and the Thwaites and Pine Island region of West Antarctica," said Jay Zwally, a glaciologist with NASA Goddard Space Flight Center in Greenbelt, Maryland, and lead author of the study, which was published on Oct. 30 in the Journal of Glaciology. "Our main disagreement is for East Antarctica and the interior of West Antarctica - there, we see an ice gain that exceeds the losses in the other areas." Zwally added that his team "measured small height changes over large areas, as well as the large changes observed over smaller areas."

Scientists calculate how much the ice sheet is growing or shrinking from the changes in surface height that are measured by the satellite altimeters. In locations where the amount of new snowfall accumulating on an ice sheet is not equal to the ice flow downward and outward to the ocean, the surface height changes and the ice-sheet mass grows or shrinks.

But it might only take a few decades for Antarctica's growth to reverse, according to Zwally. "If the losses of the Antarctic Peninsula and parts of West Antarctica continue to increase at the same rate they've been increasing for the last two decades, the losses will catch up with the long-term gain in East Antarctica in 20 or 30 years—I don't think there will be enough snowfall increase to offset these losses."

The study analyzed changes in the surface height of the Antarctic ice sheet measured by radar altimeters on two European Space Agency European Remote Sensing (ERS) satellites, spanning from 1992 to 2001, and by the laser altimeter on NASA's Ice, Cloud, and land Elevation Satellite (ICESat) from 2003 to 2008.

Zwally said that while other scientists have assumed that the gains in elevation seen in East Antarctica are due to recent increases in snow accumulation, his team used meteorological data beginning in 1979 to show that the snowfall in East Antarctica actually decreased by 11 billion tons per year during both the ERS and ICESat periods. They also used information on snow accumulation for tens of thousands of years, derived by other scientists from ice cores, to conclude that East Antarctica has been thickening for a very long time.

"At the end of the last Ice Age, the air became warmer and carried more moisture across the continent, doubling the amount of snow dropped on the ice sheet," Zwally said.

The extra snowfall that began 10,000 years ago has been slowly accumulating on the ice sheet and compacting into solid ice over millennia, thickening the ice in East Antarctica and the interior of West Antarctica by an average of 0.7 inches (1.7 centimeters) per year. This small thickening, sustained over thousands of years and spread over the vast expanse of these sectors of Antarctica, corresponds to a very large gain of ice - enough to outweigh the losses from fast-flowing glaciers in other parts of the continent and reduce global sea level rise.

Zwally's team calculated that the mass gain from the thickening of East Antarctica remained steady from 1992 to 2008 at 200 billion tons per year, while the ice losses from the coastal regions of West Antarctica and the Antarctic Peninsula increased by 65 billion tons per year.

"The good news is that Antarctica is not currently contributing to sea level rise, but is taking 0.23 millimeters per year away," Zwally said. "But this is also bad news. If the 0.27 millimeters per year of sea level rise attributed to Antarctica in the IPCC report is not really coming from Antarctica, there must be some other contribution to sea level rise that is not accounted for."

"The new study highlights the difficulties of measuring the small changes in ice height happening in East Antarctica," said Ben Smith, a glaciologist with the University of Washington in Seattle who was not involved in Zwally's study.

"Doing altimetry accurately for very large areas is extraordinarily difficult, and there are measurements of snow accumulation that need to be done independently to understand what's happening in these places," Smith said.

To help accurately measure changes in Antarctica, NASA is developing the successor to the ICESat mission, ICESat-2, which is scheduled to launch in 2018. "ICESat-2 will measure changes in the ice sheet within the thickness of a No. 2 pencil," said Tom Neumann, a glaciologist at Goddard and deputy project scientist for ICESat-2. "It will contribute to solving the problem of Antarctica's mass balance by providing a long-term record of elevation changes."

While floating Arctic sea ice is more vulnerable to current changes in climate, Antarctic ice is much more stable and is not in danger of disappearing anytime soon.

Please note the title is not claiming the ocean overall is going down by a net .23mm. It is specifically about Antarctica, which is sitting under around 90% of the ice on the surface of Earth. This thread is not for arguing about whether or not the climate changes, it is about highlighting a place where negative feedback factors(increased precipitation) can occur and help to counter melting and ocean level trends.

[I Push Buttons]

I would say inb4 global warming deniers, but they ban you for using the phrase inb4, so I will simply acknowledge this post and thank you for your contribution to the forum.

[the game]

I would say inb4 global warming deniers, but they ban you for using the phrase inb4, so I will simply acknowledge this post and thank you for your contribution to the forum.

technically inb4 isn't a phrase. It's just 3 letters and the number 4.

[Puupi]

The ozone layer is strengthening there, too.

[ButterBeast]

woo time to eat meat 3 times a day and throw plastic in the sea again! can't wait for the celebratory Tirebonfire!

[Hey There Guys its Metro]

I dont think people fully realize just how minute the temperature difference is when we are talking about Global Warming.
Some places are absolutely still getting colder, but on average, the MASSIVE FUCKING SPHERE we live on is going up by less than a quarter of a degrees every few decades.

[derpkitteh]

whether or not we're destroying the planet doesn't matter, because fossil fuels will lead to more war and death. we'll destroy ourselves before the planet goes.

moving to clean, renewable energy sources is better for humanity as a whole. fossil fuels don't last forever, and we'll just be mired in resource wars if we continue to depend on them.

[Everwake]

I dont think people fully realize just how minute the temperature difference is when we are talking about Global Warming.
Some places are absolutely still getting colder, but on average, the MASSIVE FUCKING SPHERE we live on is going up by less than a quarter of a degrees every few decades.

Sounds like nothing now, but tell that to humans living 500-1000 years from now. Let's just hope technology can keep up with our wasting.

[Rukh]

The ozone layer is strengthening there, too.

http://www.usatoday.com/story/weathe...ever/74812810/

Still has a ways to go :P It does show that we really can fix things though, if we stop burying our heads in the sand.

[Dhrizzle]

While you're correct, most people assume that a 1-3 degree thing is Fahrenheit, when it's actually Celsius.

2 degrees is 35.6 degrees Fahrenheit, I don't think that large of a change has happened anywhere at a consistent level without it going back down to "normal" temperatures. Eh, and also I'm not sure if the second part of that statement holds weight, because at times it's also gone down.

That's not how Fahrenheit and Celsius relate to each other. 2°C = 35.6°F because 0°C = 32°F. A change of 2°C is only a change of 3.6°F.

This is because Celsius is a scale that runs from the freezing point of water (0°C) to the boiling point of water (100°C) at sea level. Fahrenheit had some odd defining points.

[Garnier Fructis]

Yea, Fahrenheit scales like 9/5 Celsius, so if you're getting a gigantic number out of the conversion, chances are you accidentally added 32 degrees (a constant offset that cancels itself when you look at the change in temperature).

[Deleted]

You shouldn't be using something archaic like Fahrenheit anymore in 2015.

[breadisfunny]

You shouldn't be using something archaic like Fahrenheit anymore in 2015.

it isn't archaic. deal with it.

[Deleted]

it isn't archaic. deal with it.

Mile, yard, foot and inch want to invite you to a swanky party. You seem to be hip and spiffy like they are!

[breadisfunny]

exactly the imperial system is best.
not sure what ice sheets gaining .23mm has to do with global warming being refuted...

[Deathcries]

I'm curious as to people who use the metric system as their countries measurement. What size ratchet wrenches do you guys use?

[Deleted]

I'm curious as to people who use the metric system as their countries measurement. What size ratchet wrenches do you guys use?

Established system != good system.

[charan25]

I'm curious as to people who use the metric system as their countries measurement. What size ratchet wrenches do you guys use?

because obviously in this who world metric wrenches must not exist...

honestly, the metric system is so much better than the US. US has to convert stuff and memorize how many inches in a foot, feet in a yard, yards in a mile, etc. Metric, all you do is move the decimal point. Why are we still fighting this?

[PC2]

not sure what ice sheets gaining .23mm has to do with global warming being refuted...

Nobody in the thread was even saying this study refutes global warming... Sometimes I think people don't actually care about the specifics, just about attacking a minority of people they hate for not agreeing with them on everything.

Also, the study isn't about Antarctic ice sheets gaining .23mm, its saying that snowfall on the continent has been working to increase ice mass on it overall and lower the sea level by .23mm per year.

[PosPosPos]

Nobody in the thread was even saying this study refutes global warming... Sometimes I think people don't actually care about the specifics, just about attacking a minority of people they hate for not agreeing with them on everything.

Also, the study isn't about Antarctic ice sheets gaining .23mm, its saying that snowfall on the continent has been working to increase ice mass on it overall and lower the sea level by .23mm per year.

It's temporary though, due to how melting and freezing works with salinity.